Self integrating structural insert sleeve

Abstract

A self-integrating insert sleeve assembly, comprising an insert sleeve and an expander pin, for insertion into an aperture of a work piece is provided. Upon installation, the insert sleeve component is incrementally expanded by interaction with the pin, and secured to the aperture of the work piece, such that the resulting aperture of the installed insert sleeve has a predetermined diameter, and the resulting structure now contains compressive residual stresses. Thus, the installed insert sleeve may be employed as a hole repair solution, allowing for the installation of an original size fastener per structural design within a damaged and reconditioned aperture, or simply for enhanced structural fatigue life. The installation of this insert sleeve may be done through various manners, including pull type, push type, and blind type installation processes.

The invention claimed is: 
     
       1. An insert type fastener for insertion into an aperture of a work piece, comprising:
 an expander pin having a first pin end and a second pin end opposite the first pin end, the pin comprising:
 a main body portion, the main body portion comprising:
 a top portion; 
 an initial expander rings section having a series of expander annular rings; and 
 a final expander pin head section integrally connected between the top portion and the initial expander rings section; and 
 
 a tail portion comprising an elongated smooth cylindrical push rod section extending from the first pin end to the top portion of the main body portion; and 
 
 an insert sleeve having a first sleeve end and a second sleeve end, the first sleeve end having a sleeve head, the insert sleeve comprising:
 a cylindrical sleeve portion having an outer wall and an inner wall having a series of inner wall annular rings, the series of inner wall annular rings integrated within the series of expander annular rings prior to installation into the work piece; and 
 an opening, extending between the first sleeve end and the second sleeve end, adapted for receiving the expander pin; and 
 
 wherein a diameter of the elongated smooth cylindrical push rod section is smaller than a diameter of the opening of the sleeve allowing the elongated push rod section and the entire length of the expander pin to pass entirely through the opening of the sleeve. 
 
     
     
       2. The fastener of  claim 1 , wherein a surface of the outer wall is selected from at least one of smooth, a series of outer wall annular rings, waves, threads and concentric knurls. 
     
     
       3. The fastener of  claim 1 , wherein the series of inner wall annular rings comprise first diameter rings and second diameter rings, and wherein a diameter of a ring in the first diameter rings is larger than a diameter of a ring in the second diameter rings; and wherein a surface of the inner wall transitioning between the first diameter rings and the second diameter rings is smooth. 
     
     
       4. The fastener of  claim 1 , wherein the series of expander annular rings comprise first diameter rings and second diameter rings, and wherein a diameter of a ring in the first diameter rings is larger than a diameter of a ring in the second diameter rings; and wherein a surface of the initial expander rings section transitioning between the first diameter rings and the second diameter rings is smooth. 
     
     
       5. The fastener of  claim 1 , wherein a diameter of the final expander pin head section is larger than diameters of rings in the series of expander annular rings of the initial expander rings section. 
     
     
       6. The fastener of  claim 1 , wherein a portion of the final expander pin head is located outside the sleeve head.